Date   

Re: Buying Tek equipment on eBay or on Swap meets

Lawrance A. Schneider
 

On Wed, May 5, 2021 at 10:35 AM, - wrote:


You have to persistent and
probably have to visit them over and over and over
Hi,

I'm a 75 year old ECE student at the university. When they 'get rid' of something I'm there looking and maybe accepting. I've gotten things from the Physics Department (my digs years ago) and from ECE.

As to 'visiting over and over', the Ship Yard is three hours away and the Naval base is 5 hours away; Maine roads are not the best. I do use Craigs List and our local Uncle Henry's.

Maine is not a hot bed of electronics. I moved from Chicagoland to Maine because I like 'the willy-wags'; I also like Quantum Mechanics and Neotherian Rings but that is another story. I gave up a very promising carrier in physics to live here - I made a very conscious and deliberate decision to stay here. When I awake in the morning, I remind myself "I don't have to 'go home' after vacation; I LIVE HERE". I was an instructor at the Uni for years (Physics and Mathematics) and then was offered a job in the Postal Service at more then 3 times the pay! Having a family, I accepted the job; going from grant to grant is not fun. I ended up being an Electronic Technician for the PO. When I retired, I went back to the Uni as a student.

I've built my own home twice out of trees (lumber) I dragged out of my woods with my draft horse. I've repaired farm machinery and sold it for better equipment. I've repaired computers for friends and at work. In all, I've had a lot of fun (excluding the PO which was a JOB) maintaining, designing and building lots of stuff. I'm 75 and a 100% disabled vet; I've have had over 40 surgeries including 4 knee replacements and 2 shoulder replacements; I definitely appreciate Dennis's wife travails. I'm worn out physically; I have an electric chainsaw and we both run out of power at about the same time. Thus, I now play with my computers and do electronics.

I'm not hurting for 'equipment', especially at the Uni, but I am envious of what I hear many of you make note of.

Thanks, larry


Re: 577 D2 question(s)

ChuckA
 

The CR70 has 2 functions REJUVENATE and RESTORE.

From the manual:

In REJUV function, cathode and G2 are tied together. Normal filament voltage is applied and a 1K ohm resistor is in series with discharging capacitor to limit surge current. Pressing REJUV, G1 is positively biased, allowing a sudden surge current to flow from cathode to G1. This current quickly drops to zero, removing the bias on G1. This current surge cracks any coating or removes any contamination on the cathode, allowing cathode to supply proper emission current.

There are 3 levels of restoration. Restoration brings new emitting material to the surface of the cathode by removing old material. In AUTO RESTORE the CR70 cycles the beam current 3 times, in MANUAL RESTORE the tube will draw current as long as the button is pressed. In AUTO and MANUAL 1 current is limited to 100ma, MANUAL 2 current is limited to 150ma.
The filament is increased 50% to superheat the cathode and soften the old material. Cathode and G2 are tied together, places zero bias on the tube and allows maximum current to flow. No current flows until 230 volts is applied to G1. This large current "boils off" the poisoning material, allowing new emitting material to come to the surface. Maximum restoration is reached when all new emitting material is exposed and is indicated as a peak current reading on the CR70 meter.

I've only had to use the RESTORE function on the weak tubes I had to get a usable display.
The REJUVENATE function can be brutal, I have completely killed a couple of picture tubes using this function more than once on a really weak tube.

Chuck

On 5/6/2021 2:54 AM, Martin wrote:
Hi Chuck,
do you, or anyone else, have an idea what the Sencore and other rejuvenators are actually doing?

cheers
Martin

--
See Early TV at:

www.myvintagetv.com


Re: 577 D2 question(s)

greenboxmaven
 

Rejuvenators send a blast of current through the cathode to the grid and often other elements. This explodes/erodes the top layer of the cathode coating to (Hopefully!) expose an active and uncontaminated layer beneath. The nature of the pulse, it's method of current limiting, and it's waveform are all the "trade secrets" of each manufacturer. Different rejuvinators tended to work better for some manufacturers of CRTs than others.

   Bruce Gentry, KA2IVY

On 5/6/21 2:54, Martin wrote:
On Wed, May 5, 2021 at 05:44 PM, ChuckA wrote:
I've had good luck using a Sencore CR-70 restoring  a TDS-648A and a HP3562A CRT....
Hi Chuck,

do you, or anyone else, have an idea what the Sencore and other rejuvenators are actually doing?

cheers
Martin




Re: Novice X-Y Problem 2246

Alan Young <agyoung@...>
 

Thanks Jeff,
As an airline pilot I agree. I hate the Airbus for this very reason. I couldn't wait to get off the thing and get back to the 757/767.

Thanks for all of your help.

Alan


Re: Free: Tektronix manuals and catalogues

Richard Steedman
 

I'd be interested in the 7603, 7S11 and 7L5 service manuals. Email me at "richard dot steedman at gmail dot com".


Re: Novice X-Y Problem 2265

Alan Young <agyoung@...>
 

It appears that the 2246 has a problem with the X-Y mode. Long story short - each of the two inputs. When viewed individually (or comparatively in AB mode) I can see the demod signal on one channel and the RF envelope on the other, normally. However, when in X-Y mode, only by pushing the beam finder can I see anything. While pressed, it shows bothe the X and Y input only in the vertical mode. I can see each channel, but the respective inputs just modulate in the X (vertical) axis.

I have poured through the manual and nothing helpful. I guess I am looking for another scope. Didn’t pay much for this one, and it is always a gamble. So, I guess I’ll try another one. I don’t need anything esoteric as it will just be looking at RF in the 4mh-50 MHz range. So the search is on.

Thanks to all for the help and information.
Alan


Re: Transporting a 500-Series Scope without Breaking the CRT

 

I wonder if the same technology we use for impact resistant cushions is suitable. A lot of foams give back the stored energy absorbed in an impact at a faster rate than they absorb it leading to more damage than with out the foam. Not good for the back sitting on them when the aircraft you’re in thumps down hard and so on. There are a number of foams engineered to do the opposite, give the energy back slower, thus reducing the acceleration

Robin

On 6 May 2021, at 08:03, stevenhorii <sonodocsch@gmail.com> wrote:

Yep - same idea. You reduce the sudden acceleration/deceleration of an
impact.

On Thu, May 6, 2021 at 2:22 AM Dave Seiter <d.seiter@att.net> wrote:

I used to pack scopes in a similar manner, but reversed. The inner
box/foam was designed to hold the TE firmly with no (or minimal) travel
possible; while the outer box was sacrificial, with crumple zones at the
corners and edges. The 2-4" of outer padding was softer than the inner
padding, or mixed with more compressible material. One buyer commented
that the outer box looked terrible when it arrived, but the inner box (and
gear) was untouched.
-Dave
On Wednesday, May 5, 2021, 10:36:00 PM PDT, stevenhorii <
sonodocsch@gmail.com> wrote:

I once received a microscope that was quite heavy (the stand and parts
weighed about 40 pounds) that was packed in what I figured out was a very
clever method. The stand was wrapped by layers of relatively soft foam
sheeting resulting in about 3-inches all around. The various attachments
were packed with this foam and placed in small boxes. The scope and stand
were fitted into a box that was a close fit and the voids filled with more
of the soft foam that was rolled or balled up. This box then went into a
larger box. Between the two was 2" of styrofoam sheet. This is more rigid
than the foam that surrounded the scope and attachments.

I realized what this did - impacts might move the microscope in the inner
box but the soft foam would prevent sudden deceleration. If the soft foam
did not stop the movement, it would slow it down so impact with the wall of
the inner box would be much less forceful. The more rigid foam between the
two boxes would then further slow and stop any movement not stopped by the
soft foam and inner box. A similar idea seems to be in the packing used for
some delicate items that I've seen for aircraft instruments and some
transmitting tubes. It uses a foam block with a star-shaped cutout. The
item fits in the opening between the tips of the "star". These will provide
gradually increasing resistance to movement since the star points get
larger away from the center of the cutout. The basic idea is to allow for
gradual deceleration in the event of impact rather than a sudden stop.

I think the "horsehair felt" (that's what I've heard it called) works the
same way - with compression, it gives easily at first and with increasing
resistance as it is compressed further.

On Thu, May 6, 2021 at 12:21 AM - <rrrr6789@gmail.com> wrote:

It probably wasn't the rubberized horsehair that Greg was talking about
but the cardboard looking stuff that was molded to exactly fit the device
and the inside of the box. It was simply a thin walled shell, like an egg
carton. I also remember the old rubberized horsehair, the military used
it
all over the place in the 1950s and it was also very effective but it was
very thick and bulky and probably added a lot of weight to the packed
box.
The cardboard(?) shells OTOH were thin and light.

On Thu, May 6, 2021 at 12:04 AM greenboxmaven via groups.io <ka2ivy=
verizon.net@groups.io> wrote:

The packing material you referred to was likely rubberized horsehair.
It
was used extensively for packing heavy items at the time, and worked
very well. The military used it as well. In the 1960s, burning trash
was
fairly common in many places. If you threw that packing material in the
fire, everyone for a mile around knew it. PEEEEEUUUUU! I think there
was
a similar packing that used nylon strands to replace the horsehair, it
was stiffer and had a totally different smell. Oh yeah, we always saved
all of the aerisol cans, electrolytic condensers, and batteries from
the
shop to throw in the fire as well.

Bruce Gentry, KA2IVY




On 5/5/21 23:21, Greg Muir via groups.io wrote:
I vaguely remember receiving a new 524AD in a heavy cardboard box
with
a
molded rubberized fiber surrounding it forming a sort of cavity. The
material had sort of a slightly springy characteristic to it yet it
didn’t
give from the weight. Upon receiving it you simply plugged it in.

These scopes were supplied by RCA as part of their complete broadcast
television packages and if I can remember were drop shipped from Tek.
I
say “drop shipped” but don’t really mean it literally but the 60+ pound
weight of the scope may have caused them to experience the “real
thing.”

In those days we also received the larger transmitter final tubes
packed
in the same material. It seemed to be the packaging of choice in that
era.

Greg

























Re: Transporting a 500-Series Scope without Breaking the CRT

stevenhorii
 

Yep - same idea. You reduce the sudden acceleration/deceleration of an
impact.

On Thu, May 6, 2021 at 2:22 AM Dave Seiter <d.seiter@att.net> wrote:

I used to pack scopes in a similar manner, but reversed. The inner
box/foam was designed to hold the TE firmly with no (or minimal) travel
possible; while the outer box was sacrificial, with crumple zones at the
corners and edges. The 2-4" of outer padding was softer than the inner
padding, or mixed with more compressible material. One buyer commented
that the outer box looked terrible when it arrived, but the inner box (and
gear) was untouched.
-Dave
On Wednesday, May 5, 2021, 10:36:00 PM PDT, stevenhorii <
sonodocsch@gmail.com> wrote:

I once received a microscope that was quite heavy (the stand and parts
weighed about 40 pounds) that was packed in what I figured out was a very
clever method. The stand was wrapped by layers of relatively soft foam
sheeting resulting in about 3-inches all around. The various attachments
were packed with this foam and placed in small boxes. The scope and stand
were fitted into a box that was a close fit and the voids filled with more
of the soft foam that was rolled or balled up. This box then went into a
larger box. Between the two was 2" of styrofoam sheet. This is more rigid
than the foam that surrounded the scope and attachments.

I realized what this did - impacts might move the microscope in the inner
box but the soft foam would prevent sudden deceleration. If the soft foam
did not stop the movement, it would slow it down so impact with the wall of
the inner box would be much less forceful. The more rigid foam between the
two boxes would then further slow and stop any movement not stopped by the
soft foam and inner box. A similar idea seems to be in the packing used for
some delicate items that I've seen for aircraft instruments and some
transmitting tubes. It uses a foam block with a star-shaped cutout. The
item fits in the opening between the tips of the "star". These will provide
gradually increasing resistance to movement since the star points get
larger away from the center of the cutout. The basic idea is to allow for
gradual deceleration in the event of impact rather than a sudden stop.

I think the "horsehair felt" (that's what I've heard it called) works the
same way - with compression, it gives easily at first and with increasing
resistance as it is compressed further.

On Thu, May 6, 2021 at 12:21 AM - <rrrr6789@gmail.com> wrote:

It probably wasn't the rubberized horsehair that Greg was talking about
but the cardboard looking stuff that was molded to exactly fit the device
and the inside of the box. It was simply a thin walled shell, like an egg
carton. I also remember the old rubberized horsehair, the military used
it
all over the place in the 1950s and it was also very effective but it was
very thick and bulky and probably added a lot of weight to the packed
box.
The cardboard(?) shells OTOH were thin and light.

On Thu, May 6, 2021 at 12:04 AM greenboxmaven via groups.io <ka2ivy=
verizon.net@groups.io> wrote:

The packing material you referred to was likely rubberized horsehair.
It
was used extensively for packing heavy items at the time, and worked
very well. The military used it as well. In the 1960s, burning trash
was
fairly common in many places. If you threw that packing material in the
fire, everyone for a mile around knew it. PEEEEEUUUUU! I think there
was
a similar packing that used nylon strands to replace the horsehair, it
was stiffer and had a totally different smell. Oh yeah, we always saved
all of the aerisol cans, electrolytic condensers, and batteries from
the
shop to throw in the fire as well.

Bruce Gentry, KA2IVY




On 5/5/21 23:21, Greg Muir via groups.io wrote:
I vaguely remember receiving a new 524AD in a heavy cardboard box
with
a
molded rubberized fiber surrounding it forming a sort of cavity. The
material had sort of a slightly springy characteristic to it yet it
didn’t
give from the weight. Upon receiving it you simply plugged it in.

These scopes were supplied by RCA as part of their complete broadcast
television packages and if I can remember were drop shipped from Tek.
I
say “drop shipped” but don’t really mean it literally but the 60+ pound
weight of the scope may have caused them to experience the “real
thing.”

In those days we also received the larger transmitter final tubes
packed
in the same material. It seemed to be the packaging of choice in that
era.

Greg






















Re: 577 D2 question(s)

 

On Wed, May 5, 2021 at 05:44 PM, ChuckA wrote:
I've had good luck using a Sencore CR-70 restoring  a TDS-648A and a HP3562A CRT....
Hi Chuck,

do you, or anyone else, have an idea what the Sencore and other rejuvenators are actually doing?

cheers
Martin


Re: Transporting a 500-Series Scope without Breaking the CRT

Dave Seiter
 

I used to pack scopes in a similar manner, but reversed.  The inner box/foam was designed to hold the TE firmly with no (or minimal) travel possible; while the outer box was sacrificial, with crumple zones at the corners and edges.  The 2-4" of outer padding was softer than the inner padding, or mixed with more compressible material.  One buyer commented that the outer box looked terrible when it arrived, but the inner box (and gear) was untouched.
-Dave

On Wednesday, May 5, 2021, 10:36:00 PM PDT, stevenhorii <sonodocsch@gmail.com> wrote:

I once received a microscope that was quite heavy (the stand and parts
weighed about 40 pounds) that was packed in what I figured out was a very
clever method. The stand was wrapped by layers of relatively soft foam
sheeting resulting in about 3-inches all around. The various attachments
were packed with this foam and placed in small boxes. The scope and stand
were fitted into a box that was a close fit and the voids filled with more
of the soft foam that was rolled or balled up. This box then went into a
larger box. Between the two was 2" of styrofoam sheet. This is more rigid
than the foam that surrounded the scope and attachments.

I realized what this did - impacts might move the microscope in the inner
box but the soft foam would prevent sudden deceleration. If the soft foam
did not stop the movement, it would slow it down so impact with the wall of
the inner box would be much less forceful. The more rigid foam between the
two boxes would then further slow and stop any movement not stopped by the
soft foam and inner box. A similar idea seems to be in the packing used for
some delicate items that I've seen for aircraft instruments and some
transmitting tubes. It uses a foam block with a star-shaped cutout. The
item fits in the opening between the tips of the "star". These will provide
gradually increasing resistance to movement since the star points get
larger away from the center of the cutout. The basic idea is to allow for
gradual deceleration in the event of impact rather than a sudden stop.

I think the "horsehair felt" (that's what I've heard it called) works the
same way - with compression, it gives easily at first and with increasing
resistance as it is compressed further.

On Thu, May 6, 2021 at 12:21 AM - <rrrr6789@gmail.com> wrote:

  It probably wasn't the rubberized horsehair that Greg was talking about
but the cardboard looking stuff that was molded to exactly fit the device
and the inside of the box. It was simply a thin walled shell, like an egg
carton.  I also remember the old rubberized horsehair, the military used it
all over the place in the 1950s and it was also very effective but it was
very thick and bulky and probably added a lot of weight to the packed box.
The cardboard(?) shells OTOH were thin and light.

On Thu, May 6, 2021 at 12:04 AM greenboxmaven via groups.io <ka2ivy=
verizon.net@groups.io> wrote:

The packing material you referred to was likely rubberized horsehair. It
was used extensively for packing heavy items at the time, and worked
very well. The military used it as well. In the 1960s, burning trash was
fairly common in many places. If you threw that packing material in the
fire, everyone for a mile around knew it. PEEEEEUUUUU! I think there was
a similar packing that used nylon strands to replace the horsehair, it
was stiffer and had a totally different smell. Oh yeah, we always saved
all of the aerisol cans, electrolytic condensers, and batteries from the
shop to throw in the fire as well.

      Bruce Gentry, KA2IVY




On 5/5/21 23:21, Greg Muir via groups.io wrote:
I vaguely remember receiving a new 524AD in a heavy cardboard box with
a
molded rubberized fiber surrounding it forming a sort of cavity.  The
material had sort of a slightly springy characteristic to it yet it
didn’t
give from the weight.  Upon receiving it you simply plugged it in.

These scopes were supplied by RCA as part of their complete broadcast
television packages and if I can remember were drop shipped from Tek.  I
say “drop shipped” but don’t really mean it literally but the 60+ pound
weight of the scope may have caused them to experience the “real thing.”

In those days we also received the larger transmitter final tubes
packed
in the same material.  It seemed to be the packaging of choice in that
era.

Greg













Re: Transporting a 500-Series Scope without Breaking the CRT

stevenhorii
 

I once received a microscope that was quite heavy (the stand and parts
weighed about 40 pounds) that was packed in what I figured out was a very
clever method. The stand was wrapped by layers of relatively soft foam
sheeting resulting in about 3-inches all around. The various attachments
were packed with this foam and placed in small boxes. The scope and stand
were fitted into a box that was a close fit and the voids filled with more
of the soft foam that was rolled or balled up. This box then went into a
larger box. Between the two was 2" of styrofoam sheet. This is more rigid
than the foam that surrounded the scope and attachments.

I realized what this did - impacts might move the microscope in the inner
box but the soft foam would prevent sudden deceleration. If the soft foam
did not stop the movement, it would slow it down so impact with the wall of
the inner box would be much less forceful. The more rigid foam between the
two boxes would then further slow and stop any movement not stopped by the
soft foam and inner box. A similar idea seems to be in the packing used for
some delicate items that I've seen for aircraft instruments and some
transmitting tubes. It uses a foam block with a star-shaped cutout. The
item fits in the opening between the tips of the "star". These will provide
gradually increasing resistance to movement since the star points get
larger away from the center of the cutout. The basic idea is to allow for
gradual deceleration in the event of impact rather than a sudden stop.

I think the "horsehair felt" (that's what I've heard it called) works the
same way - with compression, it gives easily at first and with increasing
resistance as it is compressed further.

On Thu, May 6, 2021 at 12:21 AM - <rrrr6789@gmail.com> wrote:

It probably wasn't the rubberized horsehair that Greg was talking about
but the cardboard looking stuff that was molded to exactly fit the device
and the inside of the box. It was simply a thin walled shell, like an egg
carton. I also remember the old rubberized horsehair, the military used it
all over the place in the 1950s and it was also very effective but it was
very thick and bulky and probably added a lot of weight to the packed box.
The cardboard(?) shells OTOH were thin and light.

On Thu, May 6, 2021 at 12:04 AM greenboxmaven via groups.io <ka2ivy=
verizon.net@groups.io> wrote:

The packing material you referred to was likely rubberized horsehair. It
was used extensively for packing heavy items at the time, and worked
very well. The military used it as well. In the 1960s, burning trash was
fairly common in many places. If you threw that packing material in the
fire, everyone for a mile around knew it. PEEEEEUUUUU! I think there was
a similar packing that used nylon strands to replace the horsehair, it
was stiffer and had a totally different smell. Oh yeah, we always saved
all of the aerisol cans, electrolytic condensers, and batteries from the
shop to throw in the fire as well.

Bruce Gentry, KA2IVY




On 5/5/21 23:21, Greg Muir via groups.io wrote:
I vaguely remember receiving a new 524AD in a heavy cardboard box with
a
molded rubberized fiber surrounding it forming a sort of cavity. The
material had sort of a slightly springy characteristic to it yet it
didn’t
give from the weight. Upon receiving it you simply plugged it in.

These scopes were supplied by RCA as part of their complete broadcast
television packages and if I can remember were drop shipped from Tek. I
say “drop shipped” but don’t really mean it literally but the 60+ pound
weight of the scope may have caused them to experience the “real thing.”

In those days we also received the larger transmitter final tubes
packed
in the same material. It seemed to be the packaging of choice in that
era.

Greg













Re: Comprehensive parts list for 2430/2440

Joerg
 

Hi Mark,
this is great! Thanks so much!
Best
Joerg


Re: Novice X-Y Problem 2265

-
 

I never considered DSOs and other digitally controlled equipment as
Fly-by-Wire but that's an excellent analogy. Thanks.

On Wed, May 5, 2021 at 8:10 PM Jeff Dutky <jeff.dutky@gmail.com> wrote:

Alan,

The 2200-series WERE "cheap and flimsy" compared to the 400-series scopes
(well, the knobs and buttons were, at least. The cases were still pretty
well made), but that was by design: Tek was facing fierce competition from
Japanese manufacturers and they designed the 2200-series scopes to reduce
cost of parts and assembly (and, whether intentional, or just a fortuitous
side effect, of maintenance). The 2200-series scopes also wound up being
much lighter than the 400-series, but I'm not sure that is a cost-cutting
measure, or if it was meant as an improvement in user-experience (it
certainly is easier to haul a 2235 around than a 465).

The later 2200-series scopes, like the 2246, increased the cost cutting by
going to entirely (or mostly) digital controls, but this also allowed the
controls to be programmed by GPIB or loaded from saved settings, which was
another kind of user-experience improvement, though not one that everybody
appreciates in equal measure. Lots of folks, myself included, like solid,
direct mechanical controls rather than fly-by-wire instrumentation.

-- Jeff Dutky






Re: Transporting a 500-Series Scope without Breaking the CRT

-
 

It probably wasn't the rubberized horsehair that Greg was talking about
but the cardboard looking stuff that was molded to exactly fit the device
and the inside of the box. It was simply a thin walled shell, like an egg
carton. I also remember the old rubberized horsehair, the military used it
all over the place in the 1950s and it was also very effective but it was
very thick and bulky and probably added a lot of weight to the packed box.
The cardboard(?) shells OTOH were thin and light.

On Thu, May 6, 2021 at 12:04 AM greenboxmaven via groups.io <ka2ivy=
verizon.net@groups.io> wrote:

The packing material you referred to was likely rubberized horsehair. It
was used extensively for packing heavy items at the time, and worked
very well. The military used it as well. In the 1960s, burning trash was
fairly common in many places. If you threw that packing material in the
fire, everyone for a mile around knew it. PEEEEEUUUUU! I think there was
a similar packing that used nylon strands to replace the horsehair, it
was stiffer and had a totally different smell. Oh yeah, we always saved
all of the aerisol cans, electrolytic condensers, and batteries from the
shop to throw in the fire as well.

Bruce Gentry, KA2IVY




On 5/5/21 23:21, Greg Muir via groups.io wrote:
I vaguely remember receiving a new 524AD in a heavy cardboard box with a
molded rubberized fiber surrounding it forming a sort of cavity. The
material had sort of a slightly springy characteristic to it yet it didn’t
give from the weight. Upon receiving it you simply plugged it in.

These scopes were supplied by RCA as part of their complete broadcast
television packages and if I can remember were drop shipped from Tek. I
say “drop shipped” but don’t really mean it literally but the 60+ pound
weight of the scope may have caused them to experience the “real thing.”

In those days we also received the larger transmitter final tubes packed
in the same material. It seemed to be the packaging of choice in that era.

Greg









Re: Transporting a 500-Series Scope without Breaking the CRT

greenboxmaven
 

The packing material you referred to was likely rubberized horsehair. It was used extensively for packing heavy items at the time, and worked very well. The military used it as well. In the 1960s, burning trash was fairly common in many places. If you threw that packing material in the fire, everyone for a mile around knew it. PEEEEEUUUUU! I think there was a similar packing that used nylon strands to replace the horsehair, it was stiffer and had a totally different smell. Oh yeah, we always saved all of the aerisol cans, electrolytic condensers, and batteries from the shop to throw in the fire as well.

    Bruce Gentry, KA2IVY

On 5/5/21 23:21, Greg Muir via groups.io wrote:
I vaguely remember receiving a new 524AD in a heavy cardboard box with a molded rubberized fiber surrounding it forming a sort of cavity. The material had sort of a slightly springy characteristic to it yet it didn’t give from the weight. Upon receiving it you simply plugged it in.

These scopes were supplied by RCA as part of their complete broadcast television packages and if I can remember were drop shipped from Tek. I say “drop shipped” but don’t really mean it literally but the 60+ pound weight of the scope may have caused them to experience the “real thing.”

In those days we also received the larger transmitter final tubes packed in the same material. It seemed to be the packaging of choice in that era.

Greg




Re: Transporting a 500-Series Scope without Breaking the CRT

Greg Muir
 

I vaguely remember receiving a new 524AD in a heavy cardboard box with a molded rubberized fiber surrounding it forming a sort of cavity. The material had sort of a slightly springy characteristic to it yet it didn’t give from the weight. Upon receiving it you simply plugged it in.

These scopes were supplied by RCA as part of their complete broadcast television packages and if I can remember were drop shipped from Tek. I say “drop shipped” but don’t really mean it literally but the 60+ pound weight of the scope may have caused them to experience the “real thing.”

In those days we also received the larger transmitter final tubes packed in the same material. It seemed to be the packaging of choice in that era.

Greg


Comprehensive parts list for 2430/2440

Mark Vincent
 

Mr. Joerg Rrichardt said I should put this list on the site for others who
want to have the list for restoring their scope. Here it is.

The parts I selected are the best in quality I could find. I want parts to
be in a piece for a long time without replacing because of a cheap part
that barely works. The part numbers are Mouser numbers. Ones that do not
have a part number after them are in the amount above with the same value.
No prices since I do not know the conversion for different countries. I did
not list the axial tantalums on the A10 and A11 boards as they rarely go
bad. They could be changed if the owner wants. R420 and R421 on the A16
board were lowered to bleed the B+ off faster. There is no reason other
than it as a random selection that is a common to find. What I called for
is a 1% type although a 5% will be fine in this case. The battery is a
larger capacity one than originally used to give a longer life. Early
models have a battery in one place and the chip to the rear while newer
ones use the Dallas type with the internal battery. This is a comprehensive
list. Check the s/n of your unit to make sure it matches parts. Higher
capacitance values are in some cases. It will filter better. The board
numbers, Axx:, are listed in order they appear in the manual. The power
supply diodes are not listed. Replace as necessary with heavier duty ones
when originals fail.

A10: C110, C111, C112, C122, C140, C141, C142, C169, C190, C202, C211,
C213, C215, C223, C263, C265, C340, C465, C468, C471, C480, C511C C523,
C524, C652, C768, C851- 47MFD 25V (40) 647-ULD1E470MDD1TD
C530- 22MFD 10V 581-TAP-226K010SRW
A11: C130, C131, C700, C701, C702- 22MFD 25V to 47MFD
A12: BT800 battery 667-TL5903P
C590, C882, C884, C886, C904- 47MFD 25V
C938- 10MFD 25V 647-ULD1H1100MDD1TD
A13: C702, C731- 22MFD 25V (2) 581-TAP226K025SRW
C881 1MFD 35V (film) (10) 80-R82DC4100DQ60J
A14: C903, C904- 47MFD 25V
A16: C105, C305- 680MFD 200V (2) 647-LGR2D681MELA40 or (2)
647-LGR2D821MELC30 for higher filtering if it will physically fit.
C128, C138, C184, C829, C900- 1MFD 35V (film)
C244- 180MFD 40V to 35V 647-UHE1V221MPD1TD
C262, C553- 840MFD 12v TO 1200MFD 16V (2) 647-UHE1C122MPD
C455- 1200MFD 6,3V TO 1500MFD 16V 647-UHE1C152MHD6
C460, C856, C956- 250MFD 20V to 330MFD 16V (3) 647-UHE1C331MPD
C461, C487, C494, C550, C585, C594, C595, CC650, C695, C947- 100MFD 25V
(11) 647-UHE1E101MED1TD
C664, C764- 4,7MFD 35V (2) 80-R82CC4470Z330J
C706, C816- ,068MFD film (2) 594-F339X136848MFP2B
C625- ,01MFD 80-F872BB103M480R
C219, C225- ,0022MFD 594-F339X122248MDA2B
C223- .001MFD 871-B32911A5102M
C750, C756- 180MFD 25V to 330MFD (2) 647-UHE1E331MPD6
R420, R421- 470,000 to 150,000 1W (2) 594-MBE04140C1503FC1
R223- 100,000 1/2W to 2W 71-CPF3100K00FHE14
R627- 150,000 1/2W 660-MF1/2CC1503F OR (100) 273-150K Xicon only sells
1/2W in packs of 100
A17: C218- 4,7MFD 100V 647-ULD2A4R7MDD1TD
C317- 10MFD 100V 647-ULD-2A100MED1TD
C613- 100MFD 25V 647-UHE1E101MED1TA
A10: R220, R512, 360 1/2W to 1W (2) 279-H4P360RFZA
A17: R245- 357,000 1/2W 594-HVR3700003573FR5
R246- 442,000 1/2W 603-MFR50SFTE52-442K
R247- 121,000 1W 71-CCF60-121K-E3
R248- 169,000 1W (2) 71-CMF5584K500FHEK (put these two in series)
R689- 357,000 1W MFR100FTE52-330K in series with 756-MFR4-27KFI
Optional- change the two NTC from the mains input from 5 ohms to 10 ohms to
reduce inrush current. (2) 527-CL60

Use a high deg. C m/k (4 or more) heatsink compound from heatsink to inside
base to help transfer heat and on any devices on a heatsink. Something like
MX-4 compound. Using this compound is advised for the 2465/7 series. Put
the compound on the CCD chips with the black heatsinks.The RIFA capacitors
have been speced and changed manufacturer to X1 values which will easily
handle 230/240V mains. The voltage rating of these is higher than the X2
types. Be sure to oil the fan with a heavier oil. That has not been
lubricated since it was new. Using a shielded mains cord will help keep
noise from being radiated from the cord by the noise coming in and noise
generated from the supply. Any FAIL modes might change to PASS after
replacing the battery and power cycling it a couple of times. My 2440 did
this. I do not know how it went from FAIL to PASS without calibration
unless the internal resistance of the new battery is the reason even though
the original checked good with a VTVM.

Mark


Re: 575 restoration

Mark Vincent
 

Paul,

Increasing C811 will not hurt. Higher capacitance will reduce the noise at that circuit. I mentioned Orange Drops since those are well known. The ones you have in stock are fine. Replacing an axial to radial is fine. What John said is correct about noise sources! Invest in a Isobar power strip. Those are worth the cost. A shielded power cord will also help.

If you replace any of the electrolytics, use Nichcion LGR, LGZ (for 82mfd or larger 450V), ULD, UCY or UHE. These are low ESR which filter high frequency noise better than the originals or new general purpose electrolytics either 85 or 105C that are not low ESR. These ones I listed are also long life, 5000-20000 hours. Adding a ,01mfd 1kV ceramic across electrolytics will help with noise reduction. A Corcom line filter may be needed underside if the noise is still there. I would mount it as to not drill any holes to keep the piece original. This type would be with flying leads on each end.

You can change the light source if that is a noise generator. Using a lamp with a filament will not generate noise, e.g. carbon filament, tungsten or halogen. A small VARIAC can be used to dim the lamp when desired. That will be a linear way that does not generate noise like a standard triac lamp/motor dimmer.

Mark

Mark


Re: Novice X-Y Problem 2265

 

Alan,

The 2200-series WERE "cheap and flimsy" compared to the 400-series scopes (well, the knobs and buttons were, at least. The cases were still pretty well made), but that was by design: Tek was facing fierce competition from Japanese manufacturers and they designed the 2200-series scopes to reduce cost of parts and assembly (and, whether intentional, or just a fortuitous side effect, of maintenance). The 2200-series scopes also wound up being much lighter than the 400-series, but I'm not sure that is a cost-cutting measure, or if it was meant as an improvement in user-experience (it certainly is easier to haul a 2235 around than a 465).

The later 2200-series scopes, like the 2246, increased the cost cutting by going to entirely (or mostly) digital controls, but this also allowed the controls to be programmed by GPIB or loaded from saved settings, which was another kind of user-experience improvement, though not one that everybody appreciates in equal measure. Lots of folks, myself included, like solid, direct mechanical controls rather than fly-by-wire instrumentation.

-- Jeff Dutky


Re: Novice X-Y Problem 2265

Wayne
 

Good clarification--I think you are correct on the single blink, but can't remember for sure.

Actually, you might still be able to get it to work--there may not be a problem here. Since you can't seem to turn everything off in the MODE section, If you just leave chan 2 on, and ground the chan 2 input (both lights off), you should still be able to get a horizontal line if there is a signal on the channel 1 input. If you are feeding the square wave probe compensation ("calibrator") signal into chan 1, the square wave will result in two dots in the horizontal plane, due to the "dwell time" of the signal at the positive and negative portions of the square wave. If you briefly turn up the intensity, you should see a faint line between the dots, representing the rise/fall portions of the square wave. Just put your X and Y signals in as I said in the previous post, and it ought to work if all is OK with the scope.

I understand your "cheap and flimsy" comment after using the 465; I feel the same way, but I have to say I find it very nice to have a much lighter scope to carry around. And both my 2245A and 2247A work very well. And all of them, in my estimation, are nicer to use than the new digital scopes that have one knob with many functions that you are always having to select with push buttons. The older ones are much faster to use, at least for me.

6001 - 6020 of 188092